The project is developing information processing models of cognitive anomalies in individuals at risk for severe psychopathology and, once those models are adequately developed, intends to develop preventive interventions to reduce the risk of deterioration. The specific aims of the project continue unchanged: 1) To refine objective psychophysiological criteria for identifying older adolescents and young adults at risk for severe psychopathology. 2) To characterize the high-risk subjects clinically, on the basis of a diagnostic interview, and to explore any psychopathology already present and the covariation of clinical and psychophysiological phenomena. 3) To develop and test theories of subtle information processing abnormalities in these subjects, preparatory to developing cognitively oriented preventive interventions targeted at those abnormalities. With the goal of developing preventive interventions, the present project attempts to integrate several aspects of research on individuals at risk for schizophrenia and sever mood disorder. In the coming project period we will emphasize (a) well established deficits in the orienting response (OR) and (b) basic information processing deficits, particularly emphasizing event-related brain potential (ERP) measures of competition among cognitive processes for attentional resources. This research converges on a unified understanding of cognitive deficits in subjects at risk for severe psychopathology. Five groups of nonpatients (anhedonics, perceptual aberrators, dysthymics, cyclothymics, controls) will be studied in 2 ways: structured clinical interview and psychophysiological recording during cognitive tasks. Important results to date include several interesting autonomic and CNS (ERP) orienting response relationships, unusual sensory gating evidenced in the P50 component in the ERP, significantly enhanced N200 in the ERP of groups defined by screening questionnaires or by diagnostic interview, and significantly reduced P300 in the ERP of two groups. We propose a theoretical integration of the psychophysiological findings for these at-risk groups. We wish to follow up these findings with further studies of these groups, emphasizing the orienting, sensory gating, and P300 effects associated with cognitive resource allocation difficulties.